When our school implemented AP Physics 1, I wanted to include a project that would extend over time, use more advanced data analysis, and teach students about handling experimental error. Using a donated 5-inch Newtonian telescope and an entry-level digital camera, the students gathered data from digital images of the four Galilean moons, Io,…

While perusing various websites in search of a more challenging lab for my students, I came across a number of ideas where replacing the string in an Atwood's machine with a simple ball chain like the kind found in lamp pulls created an interesting system to investigate. The replacement of the string produced a nice nonuniform acceleration, but…